{
  "abstract": "Background The hydrogen/methane breath test is a non-invasive method for assessing gut microbiota metabolism, primarily used to diagnose small intestinal bacterial overgrowth (SIBO) and intestinal methanogen overgrowth (IMO). Baseline data on abnormal test results in routine health check-up populations are currently lacking. Clarifying the distribution patterns of abnormal breath test profiles in this population can provide epidemiological support for early gut health screening and stratified intervention, and lay the foundation for exploring the association between gut microbiota metabolic abnormalities and long-term digestive diseases as well as systemic health outcomes, thereby offering important clinical translational value.Methods Fasting breath test results from individuals undergoing health check-ups at the Health Management Center of our hospital between January and March 2026 were retrospectively analyzed. Results were classified as: normal (H 2<10 ppm, CH4<10 ppm); isolated hydrogen elevation (H2≥10 ppm, CH4<10 ppm, SIBO phenotype); isolated methane elevation (CH4≥10 ppm, H2<10 ppm, IMO phenotype); and combined elevation (both≥10 ppm). Associations between abnormal test results and age and sex were analyzed.Results A total of 2,995 individuals were included, of whom 1,742 (58.2%) were female and 1,253 (41.8%) were male, with a mean age of 41.3 years (range 20–83 years). The overall prevalence of abnormal results was 30.2%, including isolated elevated hydrogen (H 2≥10 ppm, CH4<10 ppm) in 21.1% of participants, isolated elevated methane (CH4≥10 ppm, H2<10 ppm) in 6.2%, and combined elevation of both hydrogen and methane (both≥10 ppm) in 2.9%. The abnormality rate was significantly higher in females than in males (32.1% vs. 27.6%, P=0.006), with the difference primarily attributable to isolated elevated hydrogen (22.5% vs. 19.1%). Methane elevation increased with age, peaking at 9.3% in the 50–70 years age group, while isolated elevated hydrogen was most common in the 20–40 years age group (24.2%).Conclusions In a large health check-up population, the prevalence of abnormal fasting hydrogen/methane breath tests was 30.2%, with isolated hydrogen elevation being the most common pattern, and methane elevation increasing with age. This study provides real-world baseline data for clinical interpretation and future research.",
  "authors": [
    {
      "affiliations": [
        "The Affiliated Guangdong Second Provincial General Hospital of Jinan University, China"
      ],
      "name": "Wenhui Tan"
    },
    {
      "affiliations": [
        "The Affiliated Guangdong Second Provincial General Hospital of Jinan University, China"
      ],
      "name": "Xiaodong Chen"
    },
    {
      "affiliations": [
        "The Affiliated Guangdong Second Provincial General Hospital of Jinan University, China"
      ],
      "name": "Lili Ye"
    }
  ],
  "title": "IDDF2026-ABS-0516 Prevalence and demographic characteristics of abnormal hydrogen/methane breath tests in a large health check-up population",
  "uid": "6cb06b00-ef68-5fcf-9320-e3f6199c00e2"
}